Before using armed forces to try to resolve a political problem, it is always wise to listen to what military men advise.
This would seem to be plain common sense. And yet as we enter the 13th day of the Nato bombing of Yugoslavia, it is becoming increasingly apparent that it is the politicians - in particular President Bill Clinton and Prime Minister Tony Blair - who are dictating military matters.
During the Gulf War, once the conflict got under way, it was the generals who gave the orders. Unfortunately, the outcome was that the military men, able to unleash a dazzling array of smart weapons which had never before seen action, made it look all too easy.
But this apparent ease overshadowed the fact that it was also won by meticulous military planning: every step was carefully plotted and completed before the next was taken.
As a result, the politicians now appear to be blinded by the idea that smart bombs can solve any problem. These weapons turn the unpredictability of war into skilled surgery where only the bad guys get zapped.
All you have to do is point a cruise missile at a dictator's head and he will cave in. But the politicians, and anyone else who previously thought similarly within Nato, are going to have to rethink their assumptions, because they are now staring a potentially catastrophic defeat right in the face.